package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisIdWorker redisIdWorker;
    
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024*1024);
    private static final ExecutorService SECKILL_ORDER_EXECUTOR = Executors.newSingleThreadExecutor();

    @PostConstruct
    private void init(){
        SECKILL_ORDER_EXECUTOR.submit(new VoucherOrderHandle());
    }

    private class VoucherOrderHandle implements Runnable{

        @Override
        public void run() {
            while(true){
                //获取队列中订单信息
                try {
                    VoucherOrder voucherOrder = orderTasks.take();
                    //创建订单
                    handleVoucherOrder(voucherOrder);
                } catch (InterruptedException e) {
                    log.error("处理订单异常");
                }

            }
        }
    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
        //创建锁对象
        RLock lock = redissonClient.getLock("lock:order" + userId);
        //获取锁
        boolean isLock = lock.tryLock();
      if(!isLock){
           //获取锁失败
          log.error("获取锁失败");
           return ;
       }
       try {
           //获取代理对象
           proxy.createVocherOrder(voucherOrder);
       }finally {
           //释放锁
           lock.unlock();
       }
    }

    @Resource
    private RedissonClient redissonClient;

    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        //获取用户
        Long userId = UserHolder.getUser().getId();
        //执行脚本
        Long result = stringRedisTemplate.execute(SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),userId.toString());


        int r = result.intValue();
        if(r != 0 ){
            //判断购买资格，不为0没有资格
            return Result.fail(r == 1 ? "库存不足" : "不能重复下单");
        }

        //为0，有购买资格
        VoucherOrder voucherOrder = new VoucherOrder();
        //5、1获取订单id
        long orderId = redisIdWorker.nextId("order");
        voucherOrder.setId(orderId);

        voucherOrder.setUserId(userId);
        //5、3获取代金券id
        voucherOrder.setVoucherId(voucherId);
        //放入阻塞队列
        orderTasks.add(voucherOrder);

        //获取代理对象
        proxy = (IVoucherOrderService) AopContext.currentProxy();


        //返回订单id
        return Result.ok(orderId);
    }


//    @Override
//
//    public Result seckillVoucher(Long voucherId) {
//        //1、查询优惠券信息
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//
//        //2、判断秒杀是否开始
//        if(LocalDateTime.now().isBefore(voucher.getBeginTime())){
//            //2.1没开始返回异常
//            return Result.fail("秒杀尚未开始");
//        }
//        //判断秒杀是否结束
//        if(LocalDateTime.now().isAfter(voucher.getEndTime())){
//            return Result.fail("秒杀已结束");
//        }
//
//        //3、秒杀开始进行库存判断
//        if(voucher.getStock()<1){
//            //3.1库存不足返回异常
//            return Result.fail("库存不足");
//        }
//        Long userId = UserHolder.getUser().getId();
//
//        //4、一人一单
//        //创建锁对象
//        //SimpleRedisLock lock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
//        RLock lock = redissonClient.getLock("lock:order" + userId);
//        //获取锁
//        boolean isLock = lock.tryLock();
//        if(!isLock){
//            //获取锁失败
//            return Result.fail("请勿重复下单");
//        }
//        try {
//            //获取代理对象
//            //获取代理对象
//            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//            return proxy.createVocherOrder(voucherId);
//        }finally {
//            //释放锁
//            lock.unlock();
//        }
//    }
    @Transactional
    public  void createVocherOrder(VoucherOrder voucherOrder) {
        Long userId = voucherOrder.getUserId();
            //4、一人一单
            Integer count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
            if (count > 0) {
                log.error("用户已经购买过一次");
            }
            //5、库存充足，扣减库存
            boolean success = seckillVoucherService.update().
                    setSql("stock=stock-1").eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0).update();
            if (!success) {
                log.error("库存不足");
            }

            //6、创建订单
            save(voucherOrder);



    }
}
